Roll-up closures such as blinds or roll-up doors are known in the art; they use outwardly-slidable securing pins to prevent the closure from being opened by unauthorized persons. For this purpose, and as disclosed in DE-PS 30 19 566 or DE-OS 25 21 183, an arrangement is taught where the lowest slat is provided with at least one securing pin that is slidable sideways. The pin works together with a spring whose normal bias forces the pin to slide out of an existing pin recess. When the roll-up blind or roll-up door is in a closed state, there is no pulling force to act against the tension of the spring. A pulling force is generated by means of a cable that connects the uppermost slat to the securing pin. In such an arrangement, use is made of the fact that during opening, the slats of a roll-up blind are maintained at a distance from one another, as opposed to the position of the slats when the roll-up blind is being closed. During opening, the creation of distances between the slats results in the cable being tensioned, thereby transmitting a pulling force to the securing pin. Thus, during opening (and also during closing), the securing pin is retracted by means of the pull cable. In fully closed position, the pull cable is in a relaxed condition and the pin is slid outwardly by the force of the spring and into a lateral recesses of a surrounding frame. If, during a break-in attempt, the uppermost slat is lifted up, the slats will be separated from one another, which will thus cause the pull cable to become taut, which will cause the securing pins to retract, the result of which being that the roll-up blind, or the roll-up door, can be unlocked.
An object of this invention, therefore, is the development of a roll-up closure security system for the purpose of eliminating the possibility of forced entry. With this invention, not only can this be accomplished by inexpensive means, but the securing device can also be simply installed.